Scale dependence of landscape-structure-based estimation of abundance of Eurasian skylark (Alauda arvensis)

The habitat and occurrence of farmland birds are strongly determined by the agricultural-landscape structure. Changes in land cover composition configuration one main causes significant decline abundance Eurasian skylark (Alauda arvensis) recent decades. This farmland-bird species is common agricultural areas Eurasia. In this study we investigate use factors involved Central Europe, Hungary. We used two different use/land (LULC) datasets, which were compiled at scales: Ecosystem Map Hungary (EMH), a very precise LULC map based on 0.04-ha minimum mapping unit, Corine Land (CLC) dataset, built using 25-ha unit. studied impact landscape negative-binomial generalized linear models. After identifying preferences among categories scales, calculated EMH CLC dataset-based indices (such as mean patch size fractal dimension index) preferred (arable lands, pastures, grasslands meadows) nonpreferred (artificial surfaces, forests, complex cultivation patterns waters) classes. Then compared results with field observations database Hungarian Common Bird Monitoring (MMM). On basis statistical analysis connections between skylark-abundance data, estimated for those where datasets from observation not available. also tested estimates assessing model sensitivity when input different-scale data windows (grain size). Our dataset explained 41.22% variance while rest, 58.78% accounted presumably due to local environmental considered our model. regional scale (CLC-based) estimation yielded significantly lower accuracies (33.76% 1200 m radius buffer zones 34.11% 600 zones). conclude that size) has relationship can help test usefulness limitations databases find optimal grain modelling estimating may support conservation management plans.